ATK Core Return Process
JEGS and ATK appreciate your business and want to ensure that your core return is as smooth as possible.
- Core return can be any Small Block Chevy 350ci engine, except 1992-1997 LT1 style engines
- Carburetor: Quick Fuel 680cfm vacuum secondary electric choke #793-HR-680-VS
- Balancer: 8" internal balance
- Distributor: HEI (iron gear)
- Exhaust: 1-5/8" Headers
- Flexplate/Flywheel: External balance 168 tooth 1987-Up
- Intake Manifold: Weiand Stealth dual plane #925-8150
- Firing Order: 18436572
- Fuel Pump: Holley Mechanical 110gph #510-12-327-11
- Octane: 91+
- Oil: 10W30 (Conventional / Non Synthetic) with zinc additive for first 3000 miles
- Oil Filter: Wix or K&N
- Spark Plug Gap: .035"
- Spark Plugs: Champion #RV12C or NGK #739-YR5
- Spark Plug Wires: 8mm
- Stall Converter: 2200-2500
- Timing: 34-36 Degrees
- Water Pump: OE long pump
Disclaimer: The parts listed are ATK's recommendations of parts to be used to obtain the power figures listed. Power figures can vary based on parts used by the end user. Some modifications to the vehicle may be required using these and or other aftermarket parts.
Engine Break-In Procedure
Use or break-in oil or conventional (non-synthetic) 10w30 oil with zinc additive for the first 500 miles of operation. Do not drive for long periods at any single speed, always vary your speed. Do not tow a trailer or put other heavy loads on the vehicle. It is best to avoid long periods of idling during this period. Check the engine oil and coolant levels daily.
Engines with flat tappet hydraulic cams only - Run the engine between 2,000 and 2,500 RPM's, with no-load on the engine for the first 30 minutes. Let the engine cool down completely and repeat process 2-3 more times. Do not idle the engine for any extended period at this time, this is critical to break in the camshaft.
At 500 Miles change the engine oil and filter using conventional (non-synthetic) oil with a zinc additive. Check fuel and ignition settings, adjust valves (where applicable). Drive the next 500 miles normally, without high RPM's (below 5000 RPM), hard use, or extended periods of high loading or long periods of idling.
Change the oil and oil filter again at 1,000 miles. Continue using conventional (non-synthetic) oils and zinc additive, until about 4,000 miles. At that point, you may run a quality 10w30 synthetic oil if you choose. Use of oil with zinc or a zinc additive for the life of your engine is recommended.
In 2007, ATK launched a High-Performance Division with one of the finest engine shops in the country. By reverse-engineering all of their engines, they are able to eliminate any OEM deficiencies. This makes an ATK-built crate engine have a superior design over the original engine by incorporating better components when needed. These quality-built engines are offered in three different stages for ease of finishing an engine swap. ATK HP engines feature a 24-month/unlimited mile warranty.
Classic 350 engine with great street manners, and vacuum for all your power accessories.
- Horsepower: 330 hp
- Torque: 380 lb/ft
- Seasoned OE 4 bolt main 1pc seal 1987-2000
- Bore/Stroke: 4.040" x 3.480"
- Displacement: 350ci
- Crankshaft: OE Reground 1 piece seal crank
- Balance: External rear, internal front
- Rods: OE powder metal 5.7"
- Compression Ratio: 9.1:1
- Pistons: Hypereutectic
- Rings: Moly
- Camshaft: Hydraulic flat tappet
- Cam Duration @ .050": Intake 224 / Exhaust 234
- Cam Lift: Intake .465" / Exhaust .488"
- Lobe Separation Angle: 112lsa
- Timing Chain: Double roller
Cylinder Head Information:
- Cylinder Heads: ATK cast iron
- Combustion Chamber: 76cc
- Intake Runner: 165cc
- Valve Size: 1.94" Intake / 1.50" Exhaust
- Rocker Arms: Stamped steel 1.5
Oil Pan Information:
- Oil Pan: Rear sump 5qt (not for Chevelles with steering behind crossmember, some Corvettes, and 1962-1967 Chevy II's)
- Oil Pump: Melling high volume
- Short Block
- Timing Set
- Cylinder Heads
- Valve Covers
- Timing Cover
- Oil Pan
- Oil Pump & Pickup Tube
Mid Dress Engines
- Consists of Base Engine Build
- Intake Manifold
- Water Pump
- Harmonic Balancer
- Flex Plate
- Consists of Mid Dress Engine Build
- Fuel Pump
- Carburetor or EFI
- Spark Plug Wires
- Spark Plugs
Will this engine fit in my 1968 chevy Bel air 307v8
Would this fit in a 02 Ford Ranger
will this work for my 88 IROC. Want to swap 305 tbi to a 350.
Will the 350 - 330 hp fit in 1959 Chevy truck. 3100
Can you get the pulleys and the belts with this motor installed
Does motor have holes for front motor mounts and need short shaft water pump ?
We have a 79 El Camino with a 305... with new headers and transmission. Can we swap this engine in and use those new parts?
will this engine fit under my stock 1980 corvette hood.
WARNING: Motor vehicles contain fuel, oils and fluids, battery posts, terminals and related accessories which contain lead and lead compounds and other chemicals known to the State of California to cause cancer, birth defects and other reproductive harm. These chemicals are found in vehicles, vehicle parts and accessories, both new and as replacements. When being serviced, these vehicles generate used oil, waste fluids, grease, fumes and particulates, all known to the State of California to cause cancer, birth defects, and reproductive harm.
WARNING: Some dust created by power sanding, sawing, grinding, drilling, and other construction activities contains chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. Some examples of these chemicals are: lead from lead-based paints, crystalline silica from bricks and cement and other masonry products, and arsenic and chromium from chemically treated lumber. Your risk from exposure to these chemicals varies, depending on how often you do this type of work. To reduce your exposure, work in a well-ventilated area and with approved safety equipment, such as dust masks that are specially designed to filter out microscopic particles.
WARNING: The wires of these products contain chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. Wash hands after handling.